This invention relates to a seal mechanism, and more particularly, to a seal mechanism for securely fastening the doors of a maritime shipping container.
Maritime shipping containers for containerized shipping have been increasingly popular for the shipping of products and materials overseas. A maritime shipping container is essentially the same as a semi-trailer, but without wheels. The doors of the container, which allow access to the interior of the container, are essentially the same as the doors of a semi-trailer.
Brackets are provided on the doors of the maritime shipping containers for receiving sealing devices to seal the container against unauthorized entry. Theft of the contents is a problem with maritime shipping containers, which often sit unprotected in isolated areas.
A known sealing mechanism comprises a male member which is adapted to be inserted through aligned openings in the brackets into a female member which is secured to the male member. Such sealing mechanism is relatively expensive to manufacture for it basically consists of five parts which must be separately made, machined, and assembled. The female member particularly requires considerable machining.
Another disadvantage of the prior sealing mechanism is that it can be simply altered so as to allow insider theft by employees. For example, the tip of the male member could be ground or otherwise machined to remove a small amount of material and then the tip could be polished to conceal the alteration. The prior art sealing mechanism could then be assembled in its intended manner, but a vigorous tug on the female member relative to the male member would cause the male member to slip out.
A further disadvantage of the prior art sealing mechanism is that it cannot easily accommodate misalignment of the brackets. If a door sags, for example, the holes in the brackets which receive the sealing mechanism become misaligned. The cylindrical sealing member cannot be inserted through greatly misaligned holes in the brackets to seal the doors of the container and could be inserted through slightly misaligned or offset holes only with difficulty.
In pending application Ser. No. 477,772 filed Mar. 22, 1983, by Ralph Burnett there is disclosed a seal mechanism which includes a curved male member formed from segments defining tooth means on the exterior thereof, said male member cooperating with a complementary curved female member having an insert for receiving the male member and preventing retrograde motion of the male member relative to the female member after insertion therein. While the Burnett seal mechanism shown in application Ser. No. 477,772 is an improvement over the known prior art, further refinements were conceived to reduce manufacturing costs and to additionally enhance performance of the seal mechanism.
An object of the present invention is to provide an improved seal mechanism including locking means of different internal diameter cooperating with the male member to permit the male member to move in one direction relative to the female member, but precluding retrograde movement of the male member relative to the female member.
Another object of the present invention is to provide an improved seal mechanism wherein the female member comprises a plurality of washer-like elements having different internal members for cooperative engagement with the male member.
Yet another object of the present invention is to provide an improved seal mechanism having locking means secured to the male member for securing the male member in place, the male member being constructed and arranged so as to be tamper proof when in assembled relationship with brackets to be fastened.
Still another object of the present invention is to provide a seal mechanism which includes a pin-like male member having thereon resilient retaining rings spaced apart axially and a hood-like female member having holes for receiving the male member and an internal wall member cooperating with the male member so as to preclude retrograde motion of the male member relative to the female member. Other objects and advantages will be made more apparent hereinafter.